That's what happened to an 8-month old infant. In case described in the Sept. 17 issue of Pediatrics, a little girl came to the emergency room 15 hours after swallowing a part of her sister's Water Balz expanding ball (from DuneCraft, Inc.,) that reportedly "grows to the size of a racquetball."

An X-ray revealed multiple loops of her bowel that appeared swollen, but it did not show an object causing the obstruction. Doctors hospitalized the child and monitored her for 48 hours but determined she needed surgery because symptoms of bowel obstruction were not letting up.

Bowel obstruction is a partial or complete blockage of the small intestine that prevents a person from passing refuse through the intestines.

Using a diagnostic laparoscopy, in which a surgeon makes a small cut below the belly button and inserts a tube with a tiny video camera, doctors found the offending object and made an incision in the intestine to pull out a 3.5-cm round gel ball.

Luckily, the infant improved after the operation and was eventually on a normal diet, leaving the hospital four days after surgery.

This image from doctors at Baylor College of Medicine shows how a water-expanding polymer toy ball could grow after 96 hours in water.

Pediatrics

Curious doctors then tested five Water Balz in separate beakers to see how much they grew over a 96-hour period, and saw the original size would double within two hours, double again after 12 hours but slowed down in growth through afterwards, averaging an extra 1.5-cm of growth over the remaining 84 hours. (See image to left)

"Due to the unique growth properties of these balls, there is a high likelihood that nonoperative management will fail," the doctors, lead by Dr. Oluyinka Olutoye, associate professor of surgery and pediatrics at the Baylor College of Medicine, wrote in the study. "As a result, practitioners must maintain a high degree of suspicion for the diagnosis of an unexplained intestinal obstruction in a child."

Dr. Robert Glatter, an emergency medicine physician at Lenox Hill Hospital in New York City, told CBSNews.com in an email, "In young children, especially in those less than 1 year of age, who tend to put objects in their mouth, this product could pose a serious problem if swallowed."

He also said the balls could block a child's airway - potentially traveling further to the lungs - leading to emergencies.

"If the object remains in the lungs for several days, it could also cause a child to develop respiratory distress (wheezing) and potentially pneumonia."

He says parents should closely supervise their young children during playtime and avoiding marble-sized toys for small children.

"An eight-month-old has no business being near that product," DuneCraft's CEO Grant Cleveland told Reuters, saying he was sorry to learn of the incident but labels on the product say the balls are designed for kids older than 3 . "Trying to turn it into a public risk is absurd."